US4700955A - Chucks - Google Patents

Chucks Download PDF

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Publication number
US4700955A
US4700955A US06/895,479 US89547986A US4700955A US 4700955 A US4700955 A US 4700955A US 89547986 A US89547986 A US 89547986A US 4700955 A US4700955 A US 4700955A
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US
United States
Prior art keywords
ram
fluid
piston
pressure
flow
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/895,479
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English (en)
Inventor
Joseph F. Jackson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pratt Burnerd International Ltd
Original Assignee
Pratt Burnerd International Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pratt Burnerd International Ltd filed Critical Pratt Burnerd International Ltd
Assigned to PRATT BURNERD INTERNATIONAL LIMITED, PARK WORKS, LISTER LANE, HALIFAX, WEST YORKSHIRE A BRITISH COMPANY reassignment PRATT BURNERD INTERNATIONAL LIMITED, PARK WORKS, LISTER LANE, HALIFAX, WEST YORKSHIRE A BRITISH COMPANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: JACKSON, JOSEPH F.
Application granted granted Critical
Publication of US4700955A publication Critical patent/US4700955A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
    • B23B31/02—Chucks
    • B23B31/10—Chucks characterised by the retaining or gripping devices or their immediate operating means
    • B23B31/12—Chucks with simultaneously-acting jaws, whether or not also individually adjustable
    • B23B31/16—Chucks with simultaneously-acting jaws, whether or not also individually adjustable moving radially
    • B23B31/16233—Jaws movement actuated by oblique surfaces of a coaxial control rod
    • B23B31/16254—Jaws movement actuated by oblique surfaces of a coaxial control rod using fluid-pressure means to actuate the gripping means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T279/00—Chucks or sockets
    • Y10T279/12—Chucks or sockets with fluid-pressure actuator
    • Y10T279/1208—Chucks or sockets with fluid-pressure actuator with measuring, indicating or control means

Definitions

  • the invention relates to chucks for use in holding tools or workpieces, and in particular to chucks which are controlled by a fluid-operated ram.
  • proximity probes are provided on the cylinder of the ram to detect when the piston of the ram is at each end of its stroke.
  • the invention provides a fluid-operated ram for use in actuating a device such as a chuck, the device having at least one limiting position which will impede the flow of fluid hence resulting in a build-up of fluid pressure within the ram, and means to relieve the pressure within the ram when the ram reaches at least one end of its working stroke.
  • the ram incorporates a pressure relief valve which is actuated when the piston of the ram reaches the said one end of its stroke.
  • the pressure relief valve may act to put the two sides of the piston into communication with one another.
  • ram is double-acting
  • Each pressure relief valve may act as a non-return valve when the other pressure relief valve is open.
  • Each pressure relief valve may comprise a valve member spring urged on to a valve seat and a plunger arranged to move the valve member off its valve seat when the piston reaches one end of its working stroke.
  • the ram may be associated with detection means arranged to detect when the said device reaches its limiting position.
  • the detection means may comprise a pressure switch arranged to detect a build-up of pressure within the ram.
  • the detection means may comprise means to detect that fluid flow to the ram has ceased.
  • FIG. 1 is an axial cross-section through a chuck generally similar to that described in U.S. patent application Ser. No. 525,729 but incorporating an embodiment of fluid-operated ram according to the invention;
  • FIG. 2 is a partial cross-sectional view on line II--II of FIG. 1;
  • FIG. 3 is a cross-section on line III--III of FIG. 2;
  • FIG. 4 is a view of part of FIG. 3 to an enlarged scale
  • FIG. 5 is a perspective exploded view of some of the components shown in FIG. 4.
  • FIG. 6 is a schematic pressure circuit diagram showing the connections to the chuck incorporating the embodiment of the invention.
  • the chuck shown in FIG. 1 comprises a cylinder 10 defining an annular chamber 11 in which moves a piston 12.
  • the piston has, uniformly spaced around it, three apertures 13 through which pass matingly shaped plugs 14.
  • the apertures 13 and plugs 14 are so shaped that as the piston 12 moves back and forth, the plugs 13 move radially inwardly and outwardly, to operate the jaws 15 of the chuck.
  • Fluid can be applied to one side of the piston 12 through a port 16 and to the other side through a port 17.
  • passages 18 for bolts 19 are provided.
  • the piston 12 has passages therein, provided with sealed liners 20.
  • each non-return valve comprises a valve member 22 which engages a valve seat 23.
  • the valve members are urged on to the valve seats by a compression spring 24 acting between the two valve members.
  • Each valve member has an integral plunger 25 which projects to a point which is proud of the surface of the piston 12.
  • Each plunger 25 is provided with flutes 20 to guide the movement of the valve member whilst permitting fluid flow past the plunger 25 when the valve member is moved off its associated seat.
  • Each seat 23 is provided by the end of a collar 27 which is screwed into a threaded portion of the aperture 21.
  • the piston can still be moved away from the end of its stroke when desired by reversing the flow of fluid to the cylinder.
  • the fluid will flow past the open valve member 22 but as it cannot flow in the reverse direction past the oppositely acting non-return valve, the piston will start to move again, and the open valve member 22 will in due course return to its seat 23.
  • valve members 22 relieve the pressure within the cylinder when the piston reaches the end of its working stroke, the only condition which will bring about a build-up of pressure within the cylinder is when the chuck jaws 15 securely grip a tool or workpiece. It would clearly be possible to provide an indication of this, for use in chuck control purposes, by fitting a pressure actuated switch in the supply line to the piston and cylinder. However it is common practice to provide pressure reducing valves in the supply line so that the supply pressure can be adjusted to cope with, for example, a delicate thin walled workpiece. This would mean that each time the supply pressure was adjusted, the level of operation of the pressure actuated switch would also have to be adjusted, which would be inconvenient.
  • means are provided to detect whether or not fluid is flowing to the piston and cylinder.
  • flow to the piston and cylinder substantially ceases. If however the piston reaches the end of its working stroke, flow to the piston and cylinder continues, because flow can take place through the piston itself.
  • FIG. 6 illustrates diagrammatically the cylinder 10 and piston 12.
  • a pressure supply line 28 extending to a changeover valve 20 and there is a fluid return line 3O.
  • the supply line 28 is fed from a pump 31, via a filter 32, pressure gauge 33, and pressure activated switch 34.
  • the filter 32 filters the supply from the pump
  • the pressure gauge 33 gives a visual indication of the actual pressure in the supply line
  • the pressure activated switch 34 provides a signal, for example for use with control circuitry, to indicate that the pump is providing an adequate pressure.
  • valve 29 is positioned as shown so that pressurised fluid is supplied to the port 16. This causes fluid to exhaust through port 17 to the return line 30. If it is desired to move the piston 12 to the left as viewed in FIG. 6, then the valve 29 is changed over, for example by means of a solenoid, to reverse the connections to the ports 16 and 17.
  • connections are made through a conventional rotating distributor 36 to a machine tool spindle 37 which is connected to the chuck.
  • a sharp-edged orifice 38 is provided in the return line 30.
  • a pressure actuated switch 39 is provided between the orifice 38 and the valve 29. When there is any significant flow down the return line 30, the orifice 38 causes a build-up of pressure which is detected by the pressure actuated switch 39.
  • the switch 39 can be coupled to a control circuit which will indicate a fault condition if flow continues for more than a predetermined length of time.
  • the invention is not restricted to the details of the foregoing embodiment.
  • the embodiment utilises two mirror image valves arranged back to back, the two valves could be arranged at separate locations on the piston 12, provided that the valves are interconnected by a fluid flow passage.
  • valves be arranged in the piston.
  • Valves could be aranged in the cylinder such that when the piston reaches an end of its working stroke it contacts and operates one of the valves to put the two sides of the cylinder into communication with one another.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Gripping On Spindles (AREA)
US06/895,479 1985-08-29 1986-08-11 Chucks Expired - Fee Related US4700955A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB858521514A GB8521514D0 (en) 1985-08-29 1985-08-29 Chucks
GB8521514 1985-08-29

Publications (1)

Publication Number Publication Date
US4700955A true US4700955A (en) 1987-10-20

Family

ID=10584435

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/895,479 Expired - Fee Related US4700955A (en) 1985-08-29 1986-08-11 Chucks

Country Status (5)

Country Link
US (1) US4700955A (fr)
EP (1) EP0213815B1 (fr)
JP (1) JPS6254609A (fr)
DE (1) DE3678363D1 (fr)
GB (1) GB8521514D0 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2107169A1 (fr) * 2008-03-31 2009-10-07 Deere & Company Cylindre hydraulique
US11173954B2 (en) * 2016-09-29 2021-11-16 Steering Solutions Ip Holding Corporation Power steering gear assembly having an end of travel valve assembly

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0378280A1 (fr) * 1989-01-13 1990-07-18 Charmilles Technologies S.A. Dispositif et procédé pour contrôler la variation d'un paramètre en électroérosion avec un fil-électrode
EP0383370B1 (fr) * 1989-01-13 1995-07-26 Charmilles Technologies S.A. Dispositif et procédé de contrôle pour découper par électroérosion en évitant la rupture du fil
DE69011537T2 (de) * 1989-01-13 1995-04-13 Charmilles Technologies Steuerungseinrichtung und Verfahren zum elektroerosiven Schneiden mittels einer Drahtelektrode.

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3450006A (en) * 1968-01-29 1969-06-17 Timberjack Machines Ltd Cylinder and piston assembly with automatic power release
CA928610A (en) * 1971-09-27 1973-06-19 C. Sifri Elie Fluid bypass valve
DE2245129A1 (de) * 1972-09-14 1974-03-21 Bosch Gmbh Robert Arbeitszylinder
US3924514A (en) * 1973-08-03 1975-12-09 Hardinge Brothers Inc Apparatus for actuating a work gripping device
US4221160A (en) * 1978-09-26 1980-09-09 Cushman Industries, Incorporated Fluid operating mechanism for a rotary chuck
US4326449A (en) * 1979-04-06 1982-04-27 Societe D'etude Et De Construction De Machines Pour Toutes Industries S.E.C.O.M.A., Societe Anonyme Double acting hydraulic jack with an end of stroke device
US4337687A (en) * 1980-05-23 1982-07-06 Prince Manufacturing Corporation Poppet trip device for hydraulic cylinders
US4443021A (en) * 1980-02-11 1984-04-17 Gildemeister Ag Apparatus for adjusting two end positions limiting a clamping stroke

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4189983A (en) * 1977-01-04 1980-02-26 Zahnradfabrik Friedrichshafen Ag Servomotor pressure control responsive to piston travel

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3450006A (en) * 1968-01-29 1969-06-17 Timberjack Machines Ltd Cylinder and piston assembly with automatic power release
CA928610A (en) * 1971-09-27 1973-06-19 C. Sifri Elie Fluid bypass valve
DE2245129A1 (de) * 1972-09-14 1974-03-21 Bosch Gmbh Robert Arbeitszylinder
US3924514A (en) * 1973-08-03 1975-12-09 Hardinge Brothers Inc Apparatus for actuating a work gripping device
US4221160A (en) * 1978-09-26 1980-09-09 Cushman Industries, Incorporated Fluid operating mechanism for a rotary chuck
US4326449A (en) * 1979-04-06 1982-04-27 Societe D'etude Et De Construction De Machines Pour Toutes Industries S.E.C.O.M.A., Societe Anonyme Double acting hydraulic jack with an end of stroke device
US4443021A (en) * 1980-02-11 1984-04-17 Gildemeister Ag Apparatus for adjusting two end positions limiting a clamping stroke
US4337687A (en) * 1980-05-23 1982-07-06 Prince Manufacturing Corporation Poppet trip device for hydraulic cylinders

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2107169A1 (fr) * 2008-03-31 2009-10-07 Deere & Company Cylindre hydraulique
US11173954B2 (en) * 2016-09-29 2021-11-16 Steering Solutions Ip Holding Corporation Power steering gear assembly having an end of travel valve assembly

Also Published As

Publication number Publication date
EP0213815A3 (en) 1988-08-24
EP0213815B1 (fr) 1991-03-27
GB8521514D0 (en) 1985-10-02
DE3678363D1 (de) 1991-05-02
JPS6254609A (ja) 1987-03-10
EP0213815A2 (fr) 1987-03-11

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Owner name: PRATT BURNERD INTERNATIONAL LIMITED, PARK WORKS, L

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Effective date: 19951025

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Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362